This invention relates generally to the field of collapsible reusable shipping containers, and more particularly to an improved form thereof suited for aircraft use within a cargo compartment which may have a non-planar roof line.
Most commercial aircraft used for shipping cargo have fuselages, of circular or ovate cross-section for reasons related to aerodynamics. Within this shape, a horizontal deck or floor is provided to support cargo. The area beneath the floor may be used for fuel storage and the like. The curved roof line of the cargo compartment has no planar ceiling, and unless containers are shaped to utilize the area immediately beneath the roof, this valuable cargo space is wasted.
It is known in the art to provide shipping containers having other than horizontal roof lines which are referred to as so-called "igloo" containers. Such containers have curved roof lines formed of molded materials, and while useful, they suffer from several disadvantages, the principal ones being high cost of manufacture, substantial weight, and more importantly, they are not normally capable of being collapsed to flattened condition for storage or return shipment.
In my prior patent, U.S. Pat. No. 4,860,972, granted Aug. 29, 1991, there is described a collapsible shipping container of "igloo" type, which is capable of being collapsed to generally planar condition, representing a substantial contribution to the art. However, this container has certain disadvantages in that in collapsed condition, it forms three separate parts. Further, the roof element is of substantial area, and requires substantial space in order to place it in supported condition prior to folding the same. During assembly, the roof element is not as easily manipulated into position overlying the erected side wall elements as might be desired.
The same problem exists to a substantial degree in the case of containers of the type in which the roof line of the cargo bay is planar rather than domed. Large generally rectangular containers using a separate roof are also difficult to manipulate.